26 Apr 2016; IMS (UiTø), RealFag A228. 13:00-14:00.

Boris Kruglikov

Poincare functions for some geometric structures

Poincare function is a rational function encoding the number of differential invariants of a pseudo-group action depending on the jet-order. I review the situation with the action of the diffeomorphisms group acting on natural bundles, and describe the Poincare function for a variety of important geometric structures: metrics (with various specifications), connections (with specifications), conformal structures etc. This surveys the works by many mathematicians starting from Tresse, Thomas, to more recent: Shmelev, Dubrovskiy, Lychagin and Yumaguzhin, together with my recent work.